I didn't. Had no idea until I saw today's draw of the Australian Open and noticed the first round of wheelchair tennis started today. Wheelchair tennis is in fact played at all four Opens. There's eight players in each of the men's and women's singles for the Australia Open but draws are unavailable for doubles and quads.
More information about the NEC Super Series is available here as is the current men's and women's rankings. Interestingly, no Australian or Kiwi is ranked in either men's or women's top 25.
Co-locating tournaments for people with and without disabilities makes perfect sense. It will surely increase media interest in sports for people with disabilities and therefore, increase participation. The Paralympics have been run at the same time and venue as the Olympics since 1988.
6 days ago